This invention relates to navigation systems and location-based information delivery. Specifically, this invention relates to a method and system for an efficient operating environment for interactive and real-time navigation.
Many commercial navigation systems are based on satellite-based global positioning system (GPS) devices, which have been applied in automobile navigation, see, e.g., U.S. Pat. Nos. 5,938,720; 5,928,307; 5,922,042; 5,912,635; 5,910,177; 5,904,728; 5,902,350, all incorporated herein by reference for all purposes. Such automobile navigation systems, however, are expensive and inconvenient to use. Further, many such systems are not appropriate for navigation while the user is walking. Therefore, there is a need in the art to incorporate navigation systems in personal handheld devices.
There are several technical obstacles that stand in the way of the incorporation of navigational capabilities in handheld devices for providing turn-by-turn real-time navigation services. One such obstacle is the amount of geographic data needed to provide reasonably detailed navigational information. Small handheld devices include cellular phones, personal digital assistants, or computers. The amount of embedded memory in such devices is limited and thus it is impractical for storage of large amounts of geographic information. In existing automobile navigation systems, GPS devices are employed to provide information about the location and movement of a user. Geographic information is usually stored in a geographic mapping database stored on a CD-ROM, hard-disk drive device or other large capacity storage medium.
Another obstacle is that the lack of information processing power in small devices, such as those mentioned above. For example, the information processing power of a cellular telephone is typically provided by an embedded microprocessor with limited memory. While the information processing power of embedded microprocessors is generally increasing, such processors are still not suitable for processor intensive real-time navigational tasks.
An additional obstacle is the insufficient location accuracy provided by current technology. Initial sources of inaccuracy of the GPS based systems, for example, may be imposed by the U.S. Department of Defense through Selective Availability (S/A), other sources of error are due to atmospheric and timing errors limiting the accuracy of a single GPS receiver to xc2x150 meters. Methods exist that can be used to enhance the location accuracy to about xc2x15 meters. Such methods include Enhanced GPS systems (i.e., SnapTrack) and network based system (i.e., Truepoint). These methods use a known position, such as a survey control point, as a reference point to correct the GPS position error. These methods of correcting GPS positions are referred to as Differential GPS or DGPS. The DGPS corrections can be applied to the GPS data in real-time using data telemetry (radio modems). Toward expanding the use of DGPS, the United States and Canadian Coast Guard are establishing a series of radio beacons to transmit the DGPS corrections for accurate navigation along the Great Lakes, the Mississippi River and tributaries, the Gulf Coast, and the Eastern and Western coasts of North America. However, such radio beacons are not available to consumers traveling in most inland locations.
Navigational systems are difficult to develop further because the desired accuracy depends on the particular application. For example, if the user is driving in a downtown area with closely spaced streets, a GPS location with accuracy within xc2x150 meters is not adequate to give turn-by-turn directions. In this context GPS location information is thus considered ambiguous and inappropriate for practical navigation. In other situations, providing a GPS location within xc2x150 meters is, however, perfectly adequate for navigation purposes. For example, if a user is driving on a highway in a remote area without any nearby exits, the GPS location is sufficient for calculating further navigation directions. Thus, in such a situation, the GPS location is not ambiguous.
Current automobile GPS navigation systems make use of other sensors, such as accelerometers, speedometers, etc. plus some sophisticated filtering technology to improve the accuracy of a navigational system (see, e.g., U.S. Pat. No. 5,912,635, previously incorporated by reference for all purposes). In addition, many automobile-based navigational systems use map-aiding technology as well. However, for a navigational system implemented using handheld devices, such as cellular telephones, it is impractical to have the handheld devices connected to external sensors, especially when the device is used while walking.
Applicants point out and incorporate by reference for all purposes related applications, one entitled xe2x80x9cMethod and System for an Interactive and Real-Time Distributed Navigation Systemxe2x80x9d (U.S. application Ser. No. 09/525,604) filed on Mar. 14, 2000 and another entitled xe2x80x9cMethod and System for an Interactive and Real-Time Distributed Navigation Systemxe2x80x9d (U.S. application Ser. No. 09/547,421, now U.S. Pat. No. 6,226,615 B1) filed on Apr. 11, 2000.
Accordingly, it would be desirable to provide a navigational system and service that deliver accurate navigational instructions. It would further be desirable to provide a navigational system that can be implemented using existing infrastructure and that is adaptable to new infrastructures as they become available.
It would further be desirable to provide a navigational system and service that can be implemented using handheld devices with limited computational power, as well as devices with enhanced computational power.
It would further be desirable to provide a navigational system and service that can make use of many forms of real-time information to provide accurate location calculations as well as optimal navigation paths.
It would further be desirable to provide an efficient environment to users in utilizing a pool of information including map, geographical, personal and location data.
Reference will now be made in detail to the preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings.
As will be appreciated by one of skill in the art, the present invention may be embodied as a method, data processing system or program products. Accordingly, the present invention may take the form of navigation systems, navigation methods, navigation devices, navigation software, etc. Software written according to the present invention is to be stored in a form of computer-readable medium, such as random access memory, hard disk memory or CD ROM, to be transmitted over a network, and executed by a processor.
These and other objects are provided for by a system and method for interactive real-time distributed navigation. In an embodiment of the invention, an operating environment is provided that receives a text message containing location information on a wireless device and identifies such location information for input to the navigation system. In another embodiment of the invention, location information is delimited by predetermined characters in the text message.
In another embodiment of the invention, an enhanced operating environment is provided by allowing a user of a navigational system to pre-plan locations and routes using information provided by the navigational system. Such preplanned information is stored by the navigational system for later retrieval by the user. In another embodiment, information is gathered for a user of a navigational system including recently traveled routes which can be retrieved by the user for improved entry of information to the navigation system.
In another embodiment, an enhanced operating environment is provided by allowing user of a navigational system to label locations. Such labeling is done in a pre-planned manner. Furthermore, such labeling is done to record a user""s present location.
In another embodiment, an enhanced operating environment is provided by providing navigational prompts to a user in a paced manner responsive to the user""s input to the navigational system. In another embodiment, the navigational prompts are stored to an alternative repository.
In another embodiment, the invention provides navigation prompts based on real-time traffic conditions. The traffic information can be obtained from a group of navigational service users, by observing their speeds and making comparisons with the nominal street speed limits in a map database. This traffic information assists the system to determine an optimal route for its users in real-time. At each juncture, the system dynamically determines an optimal path to get to the destination based on the traffic information. The best route can be defined based on the user""s request, for example, it can be either time or gas consumption which will be minimized.
In another embodiment, an enhanced operating environment is provided by improving a method by which a user logs into a navigational system, wherein a user password or personal identification number is associated with such user""s wireless device. In an embodiment, the wireless device transmits a wireless subscriber identification which the system associates with a user""s valid account to the navigational system.
In another embodiment, an enhanced operating environment is provided by allowing a user to input non-deterministic information. Upon processing, deterministic input is provided to the navigational system. In an embodiment, non-deterministic information is entered through a keypad, wherein the keys on the keypad are associated with more than one character. In another embodiment, non-deterministic information is entered through a keypad in an iterative manner such that the system presents deterministic information consistent with key entries as entered for subsequent entry to the navigation system.
In another embodiment, an enhanced operating environment is provided by allowing entry of information through a voice response system. In an embodiment, the performance of the voice response system is improved by limiting the voice grammars used by the system. In an embodiment, street grammars are limited by characteristics of such streets. In another embodiment, street grammars are limited by a distance from a user""s home or by a distance from a user""s present invention. In another embodiment, the performance of the voice response system is improved by providing a spelling of part of the voice response input.